Category: My Classroom Material

 

Introduction:
Oil spills are very hazardous to the environment and wildlife. Photographs of oil drenched birds and various sea animals are all in the back of our minds. Oil spills have become a greater problem as off shore drilling takes place. Studies show that about 5-10 million tons of oil is spilled every year. There are several sources for these oil spills and they include: cargo tanker spills at sea, waste oil pumping at sea, in port oil losses, and tanker accidents.

Cargo tanker washings at sea take place when the tankers use seawater as ballast to stabilize the craft after they have discharged their oil. This oil-contaminated water is then discharged back onto the ocean when the tanker is refilled. Waste oil pumping at sea takes place when dumping by ships other than tankers contributes an estimated 500,000 tons of oil annually. In port oil losses are attributed to collisions in ports and to procedures during loading and unloading of oil. This adds about 1 million tons of oil to sea pollution. Tanker accidents on the high seas or near the shore recently have added to the problem and have received great amounts of public attention. The Exxon Valdez the largest oil spill in history was carrying 1.2 million barrels of oil when in it ran into a reef off the coast of Alaska. Exploration losses occur during the search for and production of oil due to blowout of wells and accidental damage due to offshore drilling platforms. Oil can also leak form the 200,000 miles of pipeline that crosses waterways from cracks, punctures or corrosion in the pipes.

Two million barrels of motor oil are estimated to be lost every tear. Much of this oil ends up in coastal waters and shores. When one gallon of oil spilled in the ocean it can spread out for four acres. However 25% of spilled away is lost through evaporation. The remaining oil causes large amounts of oil to the marine life in the area that it was spilled. This oil will form a highly viscous material that sticks to every thing as it finds it way to the sea floor including: bird, fish, and marine mammals. Microorganisms and photo oxidation will break down the oil that does not this thick sticky substance. However oil spills that take place near shore have many different effects because the oil does not have enough time to break down. This causes many animals and much of the coastline to be covered with a very sticky black layer of oil.

When oil is spilled the short-term effects of the spill receive the most attention. The light intensity below an oil slick can be reduced by 90%. Oil films slow the amount of oxygen that is taken up by water. Polluted water has lower dissolved oxygen level than clean water. Birds that rely on the ocean for their survival are often greatly affected by spills. When oil forms a coat around the bird’s feathers it reduces the bird’s ability to fly, float and reduces the bird’s insulation ability. This causes many birds to doe from the cold, or their capability to get food. Compounds in oil such as benzene, toluene, xylene, naphthalene, and phenanthrene are toxic to man and animals. As a result many marine animals are killed as a result of an oil spill.

The long-term effects of an oil spill are not as easily seen as the short term effects. After oil has been in the water for a period of time it begins to affect many chemical messengers that animals rely on to survive such as finding food or escaping from predators. Oil is also incorporated into the animals’ body, as it becomes a part of the environment. Some marine animals that humans eat have fractions of oil in them, which can serve as a growing medium for many poisons.

Many methods have been developed to clean up oil spills. Skimmers are used to remove oil from the surface of the water. Skimmers work by skimming a thin of water and oil form the surface. Booms are used to contain the oil before it is skimmed. Clay, sawdust, straw, chopped corn and other absorbents have used to absorb spilled oil. Solvents have also been used to break the oil down. Burning the oil has even been attempted but it fails to completely break the oil down and makes a toxic smoke that contains carcinogenic compounds.

Oil is composed of many compounds that contain many hydrocarbons. The hydrocarbons of oil are broken down by fractional distillation. Since each compound of oil has different boiling points the compounds can be separated and collected by boiling the oil. Gasoline is distilled from below twenty degrees Celsius. Petroleum ether is separated from oil between twenty and sixty degrees. Ligroin is removed from the oil between sixty and one hundred degrees. Kerosene is removed form oil between 175 and 325 degrees. Many of these carbon compounds are cyclic compounds, which mean their atoms are attached to form rings.

In recent oil spills it has been learned that mechanically cleaning up the spill can be very complex, ineffective, and expensive. Mechanically cleaning up a spill depends upon the equipment available, workers and available, and normally it can only recover 10%-30% of the oil.

Biologically cleaning up oil spills is a great alternative to mechanical cleanup. Using microorganisms to clean up a spill is environmentally friendly and allows more of the spill to be cleaned up. This process involves seeding the oil spill with oil hungry microorganisms, bacteria yeasts, and fungi, and fertilizer to brake the oil down into masses of food and nontoxic cells that are absorbed into the food chain. These marine microorganisms naturally depend on hydrocarbons for survival so this is a natural alternative to mechanical methods. Fertilizers are spread out over the spill to promote the microorganism’s growth. Within days of when the organisms were applied to the spill changes in the oil can be seen. The oil noticeably is beginning to be broken down into fragments and other compounds. The remaining oil fractions become intermixed with and consumed by high forms of marine life.

This must all take place aerobically in the presence of oxygen. This explains why oil is able to be unchanged while it is underground. When oil is biologically broken down it products are acetate units, which are oxidized to carbon dioxide through the Krebs Cycle.

An aliphatic hydrocarbon is a compound that consists of carbon atoms joined together to form an open chain. Aliphatic compounds are oxidized into a two-carbon molecule, acetyl CoA that is catalyzed by a monooxygenase. The initial step of the oxidation of aliphatic hydrocarbons requires oxygen to serve as a reactant. The oxygen molecule is incorporated into the oxidized hydrocarbons and monoxygeneses are generally involved.

Investigation 1
Hypothesis:
In this investigation the bacteria Pseudomonas and the fungi Penicillium will break down the refined oil in the test tubes. The Pseudomonas species will brake the oil down more than the Penicillium species causing the water in test tube one to have a higher turbidity.

Materials:
The materials used in this investigation are as follows: 2 test tubes with caps, 60 mL of distilled water, one density test indicator strip, one test tube rack, Pseudomonas species culture, Penicillium species culture, a syringe, two 1 mL pipettes, and refined oil.

Procedure:
Begin by obtaining two tubes and labeling them tube # 1 pseudomonas, and tube #2 Penicillium. Add approximately 5 mL of distilled water to each tube. Next, place 4-5 drops of the refined oil to each test tube. Make sure to take notes of the general appearance of the color and texture of the oil. Record thee results from tube one in table one under day 0. Record the results from tube two in table two under day zero. Next, team member one in the group needs to inoculate tube one with the Pseudomonas, while team member two inoculates tube two with the Penicillium species. Do this by using a sterile pipette to add .5 mL of the assigned culture to the right tube. After completing this screw the cap on each tube tightly and invert the tube several times to mix; this mimics the wave action that would occur in the ocean. Then, place the tubes in an incubator set at thirty degrees Celsius for twenty-four hours. Make sure the cap on each tube is loosened one half turn. Make sure to invert the tubes once daily to increase the dissolved oxygen concentration in each tube. Also observe the tubes ever twenty-four hours for 3-4 days and make careful observations of the general appearance and characteristics of the oil. Also using an indicator measure the turbidity of the water in the tube every day. Record the results from tube one in table one and the results form tube two in table two.

Results:

Observations: Pseudomonas Species Application
Table 1

Observations: Penicillium Species Application
Table 2

 

         Describe the physical characteristics and appearance of oil on day 0.
    The oil on day 0 was amber yellow in color. The oil formed a thin uniform layer over the surface of the water.

         Describe any changes in the physical characteristics and appearance of the oil on Day 1 and beyond, and discuss causes for such changes.

On day 1 the oil became a light yellow. On day two the oil had began to fragment and was a more whitish color. On day three the oil broken down more into more droplike fragments. A faint ring formed around the edge of the tube. On day 4 the oil was completely broken down.

Is there a difference in the rate of oil degradation between the bacterial and fungal culture?

Yes the fungal culture slightly broke the oil down quicker.

What does turbidity indicate?

Turbidity indicates the amount of oil being broken down and becoming part of the water.

What is the turbidity level of your culture after 4 days of incubation? How long do you think your culture will continue to grow?

The turbidity was 0. I believe the culture will continue to grow for a day or two at the most because the oil is almost completely degraded.

What is the limiting growth factor in your test tubes?

The amount of oil and the lack of space in the test tube.

Research the nutritional requirements and environmental conditions that promote the growth of bacteria and fungi. Suggest optimum conditions to culture bacteria and fungi.

Bacteria and fungi grow the best in a warm damp environment.

Investigation 2
Hypothesis:
The fertilizer in the jars and the amount of space in the jars will promote more bacterial and fungal growth causing the oil to broken down quicker than in the tubes. The Pseudomonas species will brake the oil down faster than the Penicillium species.

Materials:
The materials needed for this investigation are 2 clear plastic jars with screw caps, 400 mL of distilled water, a density indicator strip, 2 grams of nutrient fertilizer, a sterile pipette, Pseudomonas species bacteria, and Penicillium species fungi.

Procedure:
Begin the investigation by pre-labeling the jars #1 Pseudomonas species, and jar 2 Penicillium species. Next, fill the jars half full with water. Using a pipette add 15-20 drops of oil, to form a thin layer in order to simulate an oil spill. Make sure to make an initial observation of the general appearance and characteristics of the oil and record the results from jar one in table 3 and the results from jar two in table 4. Then, using your fingers sprinkle a fine layer of fertilizer over the entire layer of oil. Using another pipette inoculate jar # 1 with 1.25 mL of Pseudomonas species medium and jar # 2 with 1.25 mL of Penicillium species liquid medium. Place the jars in an incubator set at thirty degrees Celsius and make sure the lids on the jars are loose to let oxygen in. Make sure to observe the jars once every 24 hours for 4 days. Record your observations in tables 3 and 4. Using a pipette, once a day blow bubbles into the liquid in the jars to increase oxygen content in the water.

Results

Observations: Pseudomonas Species Application
Table 3

 

Observations: Penicillium Species Application
Table 4

 

Describe what happens to the oil after several days of microbial degradation. Are the microbes breaking up the oil? Can you detect an increase in microbial growth?

After several days the oil has broken into many fragments and does not completely cover the surface of the water. Yes the microbes are braking up the oil. Yes I can detect an increase in microbial growth.

Is the oil over the surface completely degraded? Can you still see any remaining oil on the surface? If so, explain.

Yes, a light swirl of oil remains over the top of the water. The swirl is cloudy white. This oil still has not been completely broken down.

What happens to oil when it is biologically degraded in the ocean?

It is broken down and absorbed by the water, the bacteria, and other marine animals. This causes it to become part of the natural environment.

What is the purpose of the nutrient fertilizer used over the oil spill?

The fertilizer speeds up the growth of the bacteria and fungus. The bacteria and fungi are the in turn able to degrade more oil.

Are there any adverse effects of using fertilizer over an actual oil spill to enhance indigenous microbial growth?

Yes fertilizer can pollute the water and can cause harmful effects to marine and plant life in the ocean.

Did you observe an increase in turbidity over time? Which of the two simulations was more turbid? Explain.

Yes there was an increase in turbidity over time. The jar containing the Pseudomonas species of bacteria was more turbid. The oil in this jar had been broken down more causing the water to be darker.

Did you observe fungal and bacterial growth in the test tubes or jars? Explain.

The jars had more fungal growth because a larger amount of oil was degraded due to the jars excess space and the nutrient fertilizer used.

Based on the information provided, do you think that the microorganisms would be effected by water temperature? Would they follow the floating oil or be dissipated by shifting winds or currents? And if they did eat the oil, would the residue damage marine life?

Yes water temperatures could affect the microorganisms. The organisms would follow the oil. Finally, no the oil residue would not damage any marine life.

Based on the physical characteristics of oil and water discuss possible resulting problems associated with oil spills.

Since oil does not mix with water the oil forms a thick sledge on top of the water that sunlight can not penetrate. This harms the many plants near the spill that depend on sunlight to carry out photosynthesis. The thick oil also gets into birds feathers that can prevent a bird from flying and insulating itself. Fish can also get the thick sludge on them affecting their gills.

In this investigation, we evaluated the ability of microbes to degrade oil under optimum conditions. Based on your findings, discuss possible environmental limitations in using such a method over an actual oil spill in the ocean.

Possible environmental limitations that could prevent this technique form being used is temperature which effects the growth of the bacteria and fungus. Shifting of bacteria by waves can also propose a threat. The natural occurrence of oil becoming thicker and sinking to the ocean floor also proposes a problem.

If you had to describe which clean up method to use in actual oil spill, would you use such a bioremediation method or use a mechanical method described in the introduction? Explain your decision.

I would use biological remediation because it is able to clean up more of the oil, is possibly cheaper, and is more environmentally friendly.

Assuming that you need 10-6 lbs. of highly concentrated cell mass mixed with nutrient fertilizer for the degradation of oil covering 0.022 sq. ft, as in the simulated oil spill, estimate the amount of cell mass and fertilizer mixture in pounds that would be needed to degrade the oil covering 1 square mile of an ocean. Assume there is the same amount of oil relative to the area.

Investigation 3
Hypothesis:
The bacteria and fungus will brake down the oil in the dish but not as well as the previous two because of the sand interfering with the degradation.

Materials:
The materials used in this investigation are 2 petri dishes, 60 mL distilled water, 2 grams of nutrient fertilizer, Pseudomonas and Penicillium cultures, and a sterile pipette.

Procedure:
Begin by pre-labeling two petri dishes #1 Pseudomonas and #2 Penicillium. Then, remove the lids and line each of the petri plates with a layer of sand. Make sure to spread the sand evenly over the plate. Next to simulate the shore conditions moisten the sand with distilled water until a thin layer of residual layer of water forms over the sand. Add 15-20 drops of refined oil throughout the surface, enough to form a thin layer to simulate an oil spill. Allow the oil to spread over the whole surface. Make initial observations of the condition of the oil and place results in tables five and six. Then using your thumb, sprinkle a fine layer of fertilizer over the oil. Using the pipette add 1.25 mL of the Pseudomonas culture to dish one and 1.25 mL of the Penicillium culture to dish 2. Place the lids on the dishes and store them in an incubator set at thirty degrees Celsius. Finally once a day for four days make observations of the oil.

Results

Observations: Pseudomonas Species Application
Table Five

 

Observations: Species Penicillium Species Application
Table Six

 

 

Describe the physical and chemical changes of the oil after several days of microbial degradation.

Day 1 the is darker in some parts than others. Day 2 oil is tanish and has no beads. Day 3 the oil in parts is beady. On day 4 the oil had disappeared probably sinking into the sand.

How effective do you think such a method is when in an actual oil spill on the shore? What happens to the degraded oil and the resultant microbial mass?

This method is less effective than it is in the open ocean because the oil can soak into the sand, but it is more effective than mechanical methods. The degraded oil and microbial mass either stay in the sand or are washed out to sea.

Discuss the limitations of using a mechanical method to clean up a spill on the shore. What are the limitations of using a remediation method? Which of the two methods would be the most efficient and economical to clean up oil spills.

For the mechanical methods the water has to be smooth and still. For the remediation the bacteria do not grow as well in the sand. The remediation is more effective and economical than mechanical methods.

Discuss the effect of an oil spill on the shore would have on plant life along the shoreline protists, and other larger animals.

The oil could get on the plants preventing them from absorbing sunlight. The oil could poison protists or get on them and prevent them from moving. Larger animals could get oil in their fur and prevent them form insulating themselves. It could prevent birds form both flying and insulating themselves.

In the Alaskan oil spill chemical detergents wee not used. Why? Explain the use of detergents.

Detergents weren’t to because of the cold temperatures. Detergents are used to help break the oil down by making water a better solvent. Detergents work the best in warm water.

Discuss the potential of bioremediation procedures in detoxifying the air, water, soil, and waste materials.

In the same way it is used in an oil spill bioremediation can be used to break down harmful waste products such as sewage. Factories could use remediation to clean the air before emitting it into the environment. When an hazardous chemicals pollute the soil remediation could be used to make the soil safer. Water could be treated with bioremediation after it is used and before it is pumped into streams, rivers, and oceans.

What can be done to prevent oil spills.

Better training tanker ship captains to avoid running into obstacles that could rip into the tanker. Keeping better maintenance on the pipelines that are used to transport oil. Being careful to prevent the leakage of motor oil from cars and other machines.

How are we affected by oil spills? Discuss the physical and economic consequences of oil spills.

Oil spills prevent from enjoying the marine life of the ocean, beaches, and the ocean itself. Fish we eat can be contaminated with oil compounds. Oil spills require a lot of money to clean up so normal people usually carry this burden.

Research other energy sources that can be used to cut our dependence on oil.

The use of electric cars could lower our dependence of oil. The development of hydrogen powered fuel cell that uses water for energy could also cut our dependence on oil. Using solar power could also cut our dependence on oil.

Error Analysis:
In investigation one not properly inverting the tubes every day could have caused the results received to be inaccurate. In investigation two not evenly spreading the fertilizer completely over the oil could have caused certain regions to have more growth than others causing false results. On investigation three using the slant to attain the Pseudomonas and Penicillium instead of the liquid culture may have caused false results.

Conclusion:
Using bioremediation is clearly a great alternative that is more cost effective, environmentally friendly, and productive than mechanical methods to clean up an oil spill. Bioremediation works best when mixed with a fertilizer to promote microorganism growth and spread over the open water. When bioremediation is used on coastal areas it productivity is reduced because the oil can sink into the sand and into the ground. When used without fertilizer in the open water bioremediation is not as effective because the microorganism growth is not enhanced. All in all bioremediation is very effective in cleaning up an oil spill.

 

 

Introduction:
Throughout the years, people have become more aware of oil spills. The media has taken care of that by taking pictures of the disastrous effects that oil spills cause. Oil spills have become an increasing problem because drilling has moved offshore and huge tankers are used to transport the oil. Every year, about 5 to 10 million tons of oil is spilled into the ocean annually. Sources of sea contamination include the use of seawater to stabilize the ship after it has docked, the dirty water is dumped back out to sea. Normal ships, other than tankers, dump out about 500,000 tons of oil into the ocean every year. Another source of ocean contamination is when ships collide with each other in ports and oil is released. Loading and unloading oil into the ships usually causes some of the oil to be spilled into the ocean. Both of these accidents cause about 1 million tons of oil to contaminate the ocean. Tanker accidents are among the major sources of oil spills. The largest spill involved losing 3,000,000 barrels of oil! Offshore drilling or oil wells on shore often break or leak exposing oil directly to the ocean or to streams that eventually reach the ocean. Motor oil is also a threat, around 2 million tons of used motor oil reaches water.

When oil is spilled, around 25% of it is evaporated within days. The remaining oil attaches to almost anything it touches including organisms such as birds. Oil that gets on birds causes their feathers to stick together and they can’t fly, float, insulate themselves, or obtain food. Birds that come in contact with oil die. Most of the spilled oil sinks to the bottom of the ocean or is eaten by microorganisms. After 3 months, 15% of the original oil remains. That oil is in the form of dense, black, tarry lumps that end up on shore. Oil that is spilled far away from shore is less of a threat to organisms that live on shore because the oil has enough time to disappear. Oil that is spilled close to shore often washes up and sticks to everything, this is what makes everything die. However, oil has an effect on the marine life no matter where is it spilled. The amount of light that enters the water is reduced by 90% causing many marine plant and protist growth to decrease because of the reduced rate of photosynthesis. Oil also decreases the amount of oxygen that dissolves in water, which is bad for marine organisms. Oil is a toxin, and many marine organisms die from the contact with it. Benzene, toluene, xylene, naphthalene, and phenanthrene are some of the toxins that are in oil. Organisms that get killed because of these toxins involve fish, shellfish, worms, crabs, mircocrustaceans, and other invertebrates. Oil also interferes with chemical messengers. Chemical messengers mediate important biological processes that are important for organisms to survive. Oil blocks taste receptors on marine organisms or it mimics natural stimuli, which causes bad effects on some marine organisms. Oil that is eaten by small organisms gets passed along the food chain until, eventually, humans eat it. Oil also serves as a pesticide that can reach marine organisms and humans in very high, dangerous concentrations.

The main cause for oil spills is human error. Countermeasures to prevent oil spills are concentrated towards prevention. Skimmers are used to get the oil from the top layer of the ocean. Skimmers are attached to ships and once the oil has been picked up, it is separated from the water inside the ship. The water is then dumped back out and the oil is disposed of or reclaimed. Materials, such as straw, powdered clay, sawdust, chopped corncobs stuffed in cloth “sausages”, and other organic and inorganic absorbents are used to contain the oil in areas where they can be skimmed. Chemical dispersants such as detergents and solvents are used to get rid of the oil, but these chemicals are toxic to bottom-dwelling organisms, shore-dwelling organisms, and open water marine life. The attempt to burn oil has failed. It doesn’t undergo complete combustion and unburned black smoke contains toxic stuff. Incomplete combustible oil fractions contain carcinogens like phenathrene and anthracenes.

Oil is made up of hydrocarbons. Hydrocarbons are organic compounds consisting of only hydrogen and carbon. If oil is heated to certain degrees, the hydrocarbons will fall apart and the oil will evaporate, unfortunately, this option is not possible when oil is in the ocean because you can’t heat the entire ocean. The chief use of all the forms of petroleum is as fuel. Natural gas is used for heating, gasoline is used in cars and other combustion engines, kerosene is used in tractor and jet engines, and gas oil in Diesel engines. Kerosene and gas oil are also used for heat.

Mechanical methods to clean up oil only clean 10% to 30%. Also it takes along time and problems accumulate like limited manpower, no money, machines breaking down etc. Bioremediation only takes about 10-20 days to break down the oil. It involves spreading microbes called petrophiles over the oil. The petrophiles then degrade the oil biologically and convert it into food and non-toxic living cells. Boats, airplanes, or other vehicles are used to put the microbes over the oil. A fertilizer is also added to the mix to speed up the indigenous microbial action. The oil begins to break up and turn into a yellowish color. The oil is made up of remaining oil fractions and microbial masses, which get eaten by larger marine life. The process has to be aerobic, other wise, the microbes have little effect on the oil. So when the oil sinks down under the water, nothing happens to it, but when it is brought up out of the water, the microbes can break it down. The final products are acetate units, which are then broken into carbon dioxide by the Krebs cycle.

 

Hypothesis:
This experiment is a simulation of an oil spill in the ocean and on shore. It will prove that microbes can break down oil in a marine environment.

 

Materials:
#1- Materials used in this part of the lab included: 2 test tubes, 60 mL of distilled water, 1 density indicator strip, 1 test tube rack, oil, Pseudomonas culture, Penicillium culture, gloves, and an apron.

#2- Materials used in this part of the lab included: 2 plastic jars with caps, 400 mL of distilled water, 1 density indicator strip, 2 g of nutrient fertilizer, Pseudomonas culture, Penicillium culture, gloves, and an apron.

#3- Materials used in this part of the lab included: 2 petri dishes, 60 mL of distilled water, 2 g of nutrient fertilizer, Pseudomonas culture, Penicillium culture, gloves, and an apron.

 

Methods:
#1- First off, wash your hands for about 30 seconds before putting on your gloves and aprons. Label test tube #1 with Pseudomonas and test tube #2 with Penicillium with a marker. Add 5 mL of distilled water to each of the test tubes. Next, add 4-5 drops of oil to the test tubes until there is a fine layer of oil on the surface. Record the observations of the oil in the charts on Day 0. Insert .5 mL of Pseudomonas culture into tube #1 and .5 mL of the Penicillium culture in tube #2. Invert the test tubes several times and put them in an incubator with their caps loosened. Set the incubator at 30o C. Observe the tubes once every 24 hours for 3 days, recording your observations. Be sure to wash your hands before and after the observations for 30 seconds. Put any contaminated materials into an autoclave bag every time you observe the tubes.

 

#2- Wash your hands for about 30 seconds before putting on your gloves and aprons. Label jar #1 with Pseudomonas and jar #2 with Penicillium using a marker. Fill both of the jars half way with distilled water. Add 15-20 drops of oil into each of the jars until a thin layer has formed on the surface of the water. Observe the oil and record the observations under Day 0 on the charts. Sprinkle some nutrient fertilizer over the entire oil layer to increase the microbial growth and degradation process. Next, add 1.25 mL of Pseudomonas culture into jar #1 and 1.25 mL of the Penicillium culture in jar #2. Put the jars into the incubator at 30o C with their tops loosened. Observe the jars once every 24 hours for 3 days, recording your observations. To increase the dissolved oxygen level in the water, use a disposable pipette to blow oxygen bubbles into the water. Be sure to wash your hands before and after the observations for 30 seconds. Put any contaminated materials into an autoclave bag every time you observe the jars.

#3- Wash your hands for about 30 seconds before putting on your gloves and aprons. Label dish #1 with Pseudomonas and dish #2 with Penicillium using a marker on the lids of the petri dishes. Spread some sand into the dishes until there is about a 4-5 mm layer of sand. Spread the sand evenly on the dishes. Pour water over the sand so that a layer of water is covering the sand. Add 15-20 drops of oil into the water until there is oil spread evenly across the surface. Make observations of the oil and mark them under Day 0. Sprinkle some nutrient fertilizer over the entire oil layer to increase the microbial growth and degradation process. Next, add 1.25 mL of Pseudomonas culture into dish #1 and 1.25 mL of the Penicillium culture in dish #2. Put the jars into the incubator at 30o C. Observe the dishes once every 24 hours for 3 days, recording your observations in the tables. Be sure to wash your hands before and after the observations for 30 seconds. Put any contaminated materials into an autoclave bag every time you observe the dishes.

 

Results:
#1- Pseudomonas Table 1

 

Penicillium Table 2

 

1. Describe the physical characteristics and appearance of oil on Day 0.

 

– The oil laid on the water surface and the water was clear.

 

2. Describe any changes in the physical characteristics and appearance of the oil on Day 1 and beyond, and discuss the possible causes for such changes.

 

– The oil formed a ring around the side of the tube on top of the water. It also started to seep down the sides of the tube. As time passes, oil gets heavy and sinks.

 

3. Is there a difference in the rate of oil degradation between the bacterial and fungal cultures?

 

– The bacterial culture had a faster degradation rate than the fungal culture.

 

4. On an agar slant, can you identify which is the bacteria and which is the fungus? Describe the growth and appearance of both types of microbes. Can you think of any advantages in using the bacteria over the fungus to degrade oil?

 

– The bacteria grows in small colonies while the fungus grows largely everywhere. The bacteria also grows faster than the fungus. With this information, bacteria can quickly degrade the oil.

 

5. What does an increase in turbidity indicate?

 

– The break down of oil.

 

6. What is the turbidity level of your cultures after 4 days of incubation? How long do you think your cultures will continue to grow?

 

– 1 and 0. The cultures will continue to grow until the oil is all gone.

 

7. What is the limiting factor in your test tubes?

 

– The amount of oil and the size of the test tubes.

 

8. Research the nutritional requirements and environmental conditions that promote growth of bacteria and fungi. Suggest optimum conditions to culture bacteria and fungi.

 

– They grow in damp warm air and grow in stuff that they consume and survive.

#2- Pseudomonas Table 3

Penicillium Table 4

 

 

1. Describe what happens to the oil after several days of microbial degradation. Are the microbes breaking up the oil? Can you detect an increase in microbial growth?

 

– The oil is less on the surface and doesn’t appear as slick, it appears as small clumps on the surface. The microbes are breaking up the oil. Yes.

 

2. Is the oil over the surface completely degraded? Can you still see any remaining oil on the surface? If so, explain.

 

– No. Yes. The microbes haven’t completely degraded the oil it takes more time.

 

3. What happens to oil when it is biologically degraded in the ocean?

 

– It gets broken down into products that can be eaten and not harmful to the environment.

 

4. What is the purpose of the nutrient fertilizer used over the oil spill?

 

– To speed up the growth and speed of the microbes while they degrade the oil.

 

5. Are there any adverse effects of using fertilizer over an actual oil spill to enhance indigenous microbial growth?

 

– An in-balance in the environment will occur as more microbes develop, and the oxygen level will decrease as it becomes dissolved into the microbial growth.

 

6. Did you observe an increase in turbidity over time? Which of the 2 simulations is more turbid? Explain.

 

– Yes. The bacterial simulation is more turbid because the bacteria allows more space for the fertilizer to sink down into the water.

 

7. Did you observe more fungal and bacterial growth in the test tubes or in the jars? Explain.

 

– In the jars because there was more space and more fertilizer.

 

8. Based on the information provided, do you think that the microorganisms would be affected by water temperatures? Would they follow the floating oil or be dissipated by shifting winds or currents? And if they did eat the oil, would the residue damage marine life?

 

– Yes because the temperature affects the growth and speed of the microorganisms. I think they would follow the floating oil because the microorganisms would be stuck to the oil. The residue wouldn’t damage marine life because it isn’t toxic and marine organisms can eat it.

9. Based on the physical characteristics of oil and water discuss possible resulting problems associated with oil spills.

– The marine plants wouldn’t be able to grow because of the absence of light caused by the oil. Birds would get hurt and would die and fish would die because of the decrease in dissolved oxygen entering the water from the surface and from oil getting into their gills, clogging them.

 

10. In this investigation, we evaluated the ability of microorganisms to degrade oil under optimum conditions. Based on your findings, discuss possible environmental limitations in using such a method over an actual oil spill in the ocean.

 

– Temperature, waves/shifting of the water, winds. The temperature can cause the bacteria to grow either slowly or not at all. Waves move everything around and so do winds.

 

11. If you had to decide which clean up method to use in an actual oil spill, would you use such a bioremediation method or use a mechanical method described in the introduction? Explain you decision.

 

– I would use the bioremediation method because it is cheaper and less manpower is needed. It is also a lot faster and gets the job done.

 

#3 Pseudomonas Table 5

Penicillium Table 6

 

 

1. Describe the physical and chemical changes of the oil after several days of microbial degradation.

 

– The oil would soak into the sand.

 

2. How effective do you think such a method is when used in an actual oil spill on the shore? What happens to the degraded oil and the resultant microbial mass?

 

– The method is pretty effective because the oil eventually gets degraded and the residue sinks into the sand, out of harms way.

 

3. Discuss the physical limitations of using a mechanical method to clean up an oil spill on the shore. What are the limitations of using a bioremediation method? Which of the 2 methods would be the most efficient and economical to clean up oil spills?

 

– The amount of rocks and other physical barriers. The amount of fertilizer and the condition of the sand. The bioremediation method would most efficient for the reasons that I have already mentioned.

 

4. Discuss the effect of an oil spill on the shore would have on plant life along shorelines, protists, and other large animals.

 

– Everything would be soaked in oil. The plants would probably all die as well as protests and large animals that come into contact with the oil. It is very sticky and prevents organisms from using their senses to find food.

 

5. In the Alaskan oil spill, chemical detergents were not used. Why? Explain the use of detergents.

 

– Detergents are toxins to the environment including bottom dwelling organisms and land animals. Detergents are used to clean clothes and other non-living materials.

 

6. Discuss the potential of bioremediation procedures in detoxifying the air, water, soil, and waste materials.

 

– The procedures already go well in the water. In the air is a different story, the bacteria would have to be in the air, which would be dangerous for humans that live in that area. The same goes for soil, plants would get hurt if any of the bacteria was in the area. I think that it would do ok with waste materials in the water, nowhere else.

 

7. What can be done to prevent oil spills?

 

– The large tankers need to keep their oil protected from leaking out. Also the captains of the boats need to be very alert and watch out for any hazards that may cause a leak. Or we could just move all oil drilling on land and forget about all the tankers and other stuff.

 

8. How are we affected by oil spills? Discuss the physical, environmental and economic consequences of oil spills.

 

– Oil can act as a pesticide towards humans and if we are near a spill for too long, we could have some problems, just like with any other pesticide. Oil spills do a lot of damage to the environment. Many animals and other marine life are killed and whole sections of wilderness are destroyed. When there is an oil spill, money is needed to clean it up. So governments have to spend a lot of money to get it cleaned up.

 

9. Research other energy sources that can be used to cut our dependence on oil.

 

– Electricity has already begun to evolve into cars and other modes of transportation. This could cut down on our use of gasoline a lot. Wind and water generators also provide us with energy as well as nuclear power plants. Once the market for these resources has gone down a bit, everyone will be dependent on oil and there won’t be very many disasters like oil spills in the world.

 

Error Analysis:
If the wrong amounts of any of the substances that we put in the containers were wrong, the whole experiment could have failed. Especially if there wasn’t the correct amount of cultures inserted into the containers. It would have taken longer for the bacteria and the fungi to grow and the daily observations would have not been possible because nothing would have been visible.

 

Conclusions:
According to the results, bioremediation is a successful technique to clean up oil spills. In the first investigation, fertilizer wasn’t used and the oil wasn’t degraded that quick. Fertilizer was used in investigations 2 and 3, the oil was degraded much faster. Pseudomonas was the ideal microorganism for cleaning up the oil because it can reproduce faster and consume more of the oil than the Penicillium. In on shore spills, either microorganism is ideal because the oil was degraded and sank into the sand.

 

 

Bioremediation of Oil

 

Introduction

 

Public awareness of oil spills has increased over the years as more publicity has been focusing on this subject and the massive harm it does to our environment. The problem of oil spillage has increased as well, and recent studies suggest that 5-10 million tons of oil are spilled into the ocean annually. There are six major sources of spilled oil. The first is cargo tanker washings at sea. These oil tankers use seawater to stabilize their craft after discharging their oil, and then, the contaminated water is discharged into the sea when the tanker is refilled. Another source is waste oil pumping at sea which contributes 500,000 tons of oil annually. Also in-port oil losses are caused by collisions at port and the procedures used during loading and unloading. This contributes over one million tons annually. Exploration losses occur because of accidental damage to offshore drilling rigs and the blowout of wells. The last source is motor oil. It is assumed that over 2 million tons of unaccounted for motor oil reach coastal waters every year.

The damage oil spills can create is often underestimated. A single gallon of oil can actually spread over four acres of ocean. Oil spills can have devastating effects on marine life. Oil that remains after evaporation goes through an emulsification process that creates a highly viscous, sticky material. This material becomes thick enough to sink to the bottom of the ocean. It sticks to anything it comes in counter with including marine wildlife. Oil left after emulsification is broken down by microorganisms and photo-oxidation. After 3 months only 15% of the original oil volume remains and it forms tarry clots that float to shore. However, if the oil spill is extensive or occurred close to the shore line, the oil would not have sufficient time for emulsification and evaporation so the oil would create a viscous film of oil over any solid surface that comes in contact with the oil.

The short-term effects of these types of oil spills include four main areas of the environment. One effect is reduced light transmission. Light intensity under an oil spill can be reduced by up to 90%. This thwarts marine plant and protist growth because they can no longer use photosynthesis. Another effect is reduced amounts of dissolved oxygen in the water. Since the surface of the water is covered by the filmy oil, the water can no longer uptake oxygen. Oil spills also affect marine birds. Oil covered birds can be drowned or become handicapped. It also reduces their ability to fly and float on water, and their feathers no longer serve as insulation leaving them to die from exposure. The last area of short-term effect is the toxic effect of oil on the marine environment. Compounds such as benzene, toluene, xylene, naphthalene, and phenanthrene are toxic to man and marine life. Within only days oil spills can do massive damage to the marine life.

In addition to short-term effects, there are also long-lasting more serious effects of oil spills. The chemicals found in oil can mimic the chemical messengers found in oceanic water. This can deceive many marine animals that depend on these messengers to find food, escape from predators, or locating habitats suitable for reproduction. More stable oil components can be consumed by smaller species and passed on to animals higher up on the food chain, including humans. Oil can also serve as a concentration medium for other toxins like pesticide allowing them to reach humans and marine animals in a more potent form.

To reduce these effects, clean-up efforts must be fast and effective. There are four main mechanical methods used when cleaning an oil spill. Skimmers can be used to pull a thin layer of water off the surface and then separating the oil and the water. The oil can then be disposed of and the water returned to the ocean; however, this is only effective in calm waters. Booms or barriers can be used to contain the oil spill that will later be skimmed so it does not spread any further. Absorbent materials such as cloth, straw, powdered clay, and pine bark are spread over the spill surface. Chemical dispersants, detergents, and solvents can also be used, but these substances are toxic to the open water marine life and shore-dwelling organisms. The last mechanical method is burning the oil off the surface. This method was ineffective because oil is not completely combustible and it left carcinogens and thick toxic smoke over the area.

Bioremediation is the newest method of oil spill clean up and far more effective than any of the mechanical methods used. Mechanical methods are costly and can only remove about 10-30% of the contamination. Bioremediation makes use of indigenous oil-consuming microorganisms, called petrophiles, by enhancing and fertilizing them in their natural habitats. This microbial clean-up method cleans the oil as well as a number of other harmful pollutants and is perhaps the best, most environmentally safe process used today.

Petrophiles are very unique organisms that can naturally degrade large hydrocarbons and utilize them as a food source. This makes them singularly qualified for cleaning oil spills and even tanker bottoms containing oil residue. In bioremediation several different types of these microorganisms are used on the oil slick. They are dispersed by boats or aircraft and may be mixed with nutrients. The oil slick begins to show visible signs of degradation after only days. The microbes can then be assimilated up through the food chain leaving having no adverse effects on the marine environment.

Hydrocarbon degradation is an aerobic process. It uses oxidation to break down the large hydrocarbons in exposed petroleum into acetates and then eventually carbon dioxide. This final and complete oxidation into carbon dioxide is performed by the Krebs cycle, which creates components needed for the synthesis of amino acids and other compounds the microorganism may need.

 

Hypothesis

 

The oil in all three investigations will be visibly reduced by both oil-consuming microorganisms and this process can be measured by turbidity and the appearance of the oil on the surface. The sand in Investigation #3 may hinder or slow the degradation process.

 

Materials

 

Investigation #1: Visual Determination of Oil Degradation

The materials needed for Investigation #1 were 2 test tubes with caps, 60mL of distilled water, a density indicator strip, 1 test tube rack, 3 sterile pipettes, 8-10 drops of refined oil, .5 mL of the Pseudomonas culture, and .5 mL of the Penicillium culture.

Investigation #2: Simulated Oil Spill Clean Up in Water

The materials needed for Investigation #2 were 2 clear jars with caps, 400 mL of distilled water, a density indicator strip, 2g nutrient fertilizer, 30-40 drops of refined oil, 3 sterile pipettes, 1.25 mL of the Pseudomonas culture, and 1.25 mL of the Penicillium culture.

Investigation #3: Simulated Oil Spill along the Shore

The materials needed for Investigation #3 were 2 petri plates, 60 mL of distilled water, sand, 2 g nutrient fertilizer, 3 sterile pipettes, 30-40 drops of refined oil, 1.25 mL of the Pseudomonas culture, and 1.25 mL of the Penicillium culture.

 

Methods

 

Investigation #1: Visual Determination of Oil Degradation

Two tubes were labeled as follows: Tube #1: Pseudomonas species, Tube #2 Penicillium species. 5 mL of distilled water were added to each tube. Next, 4-5 drops of oil were added to each tube and allowed to form a thin layer over the water surface. Notes were taken on the oil’s general appearance. With a sterile pipette, Tube #1 was inoculated with 0.5 mL of the Pseudomonas culture, and Tube #2 was inoculated with 0.5 mL of the Penicillium culture. The cap was placed on both tubes and each was inverted several times allowing the microorganisms to mix with the oil. With caps loosened one-half turn, the tubes were incubated at 30° C. Each tube was observed and inverted every 24 hours for 4 days and each observation was recorded in the appropriate table.

Investigation #2: Simulated Oil Spill Clean Up in Water

The two jars were labeled as follows: Jar #1 Pseudomonas species, Jar #2 Penicillium species. Both jars were filled half way with distilled water. 15-20 drops of oil were added to each jar and allowed to spread over the entire water surface. An initial observation was taken of the oil appearance. Fertilizer was sprinkled over the entire oil layer in both jars. Using sterile pipettes, Jar #1 was inoculated with 1.25 mL of the Pseudomonas culture, and Jar #2 was inoculated with 1.25 mL of the Penicillium culture. The jars were then incubated at 30° C for four days with the caps loosened one-half turn. Observations were taken every 24 hours for the four days and a disposable pipette was used to blow bubbles into the culture after each observation.

Investigation #3: Simulated Oil Spill along the Shore

The lids of the petri plates were labeled as follows: Petri dish #1- Pseudomonas species, Petri dish #2- Penicillium culture. A layer of sand was spread 4-5 mm thick in each plate. The sand was then moistened with distilled water in both dishes. 15-20 drops of oil were added to each dish, and then fertilizer was sprinkled over the entire oil surface. Using sterile pipettes, Petri dish #1 was inoculated with 1.25 mL of the Pseudomonas culture, and Petri dish #2 was inoculated with 1.25 mL of the Penicillium culture. The petri dishes were then incubated at 30° C for four days. The plates were observed every 24 hours and recorded in the appropriate tables.

 

Results

 

Investigation #1: Visual Determination of Oil Degradation

 

Observations: Pseudomonas Species Application

Table 1

 

 

 

Observations: Penicillium Species Application

Table 2

 

 

Investigation #2: Simulated Oil Spill Clean Up in Water

 

Observations: Pseudomonas Species Application

Table 3

 

 

 

Observations: Penicillium Species Application

Table 4

 

 

Investigation #3: Simulated Oil Spill along the Shore

 

Observations: Pseudomonas Species Application

Table 5

 

 

 

Observations: Penicillium Species Application

Table 6

 

 

Investigation #1: Visual Determination of Oil Degradation Questions

 

Describe the physical characteristics and appearance of oil on Day 0.

 

The oil on Day 0 had not yet been degraded in any way. It was a transparent light amber that stayed completely separate from the water. It formed a thin, slick layer over the water surface.

 

Describe any changes in the physical characteristics and appearance of the oil on Day 1 and beyond, and discuss possible causes for such changes.

 

The oil began to get darker and lose its slick qualities. It no longer covered the entire surface of the water and was separated into sections.

 

Is there a difference in the rate of oil degradation between the bacterial and fungal cultures?

 

The bacterial culture degraded the oil slightly faster possibly because bacteria can reproduce at a faster rate asexually.

 

Can you identify which is the bacteria and which is the fungus on agar slants? Describe the growth and appearance characteristics of both types of microbes. Can you think of any advantages in using bacteria over fungus to degrade oil?

 

The fungal colonies are larger than that of bacteria, but the bacteria was spread over a larger area and had more numerous smaller colonies. Bacteria would be more advantageous because it could spread over a larger area faster because it reproduces quickly and abundantly.

 

What does an increase in turbidity indicate?

 

An increase in turbidity indicates the break down of oil and the growth of colonies.

 

What is the turbidity level of your cultures after four days of incubation? How long do you think your cultures will continue to grow?

 

The turbidity of our culture was 1 after four days of incubation. The colonies will most likely grow until all the available oil has been degraded.

 

What is the limiting growth factor in your test tubes?

 

The amount of oil available limits growth in our test tubes and also possibly the amount of surface area.

 

Suggest optimum conditions that promote growth of bacteria and fungi. Suggest optimum conditions to culture bacteria and fungi.

 

Bacteria and fungi grow in any damp, warm area where there is any kind of available food source however optimum growth conditions are probably at about 30° C.

Investigation #2: Simulated Oil Spill Clean Up in Water

 

Describe what happens to oil after several days of microbial degradation. Are the microbes breaking up the oil? Can you detect an increase in microbial growth?

 

Oil degraded by microorganisms begins to appear darker and less slick and no longer covers the entire surface of the water. It is also less transparent and less oil appears on the surface. Microbial growth and oil breakdown can be detected by measuring the turbidity of the water.

 

Is the oil over the surface completely degraded? Can you still see any oil remaining on the surface? If so, explain.

 

The oil on the surface is not completely degraded and remaining oil is still visible on the surface. Four days did not allow the degradation process to complete and the smaller area may have caused the oil to be more concentrated than in an actual spill.

 

What happens to oil when it is biologically degraded in the ocean?

 

Oil that remains after evaporation goes through an emulsification process that creates a highly viscous, sticky material. This material becomes thick enough to sink to the bottom of the ocean. It sticks to anything it comes in counter with including marine wildlife. Oil left after emulsification is broken down by microorganisms and photo-oxidation. After 3 months only 15% of the original oil volume remains and it forms tarry clots that float to shore.

 

What is the purpose of the nutrient fertilizer used over the oil spill?

 

Nutrient fertilizer is used to enhance and speed the degradation of oil by increasing the bacterial and fungal growth.

 

Are there any adverse effects of using a fertilizer over an actual oil spill to enhance indigenous microbial growth?

 

Bioremediation is perhaps the most environmentally safe process of oil removal used today. It uses indigenous microbial growth so it does not introduce any new species that may damage the strict ecosystem. An increase in this one type of organism may cause a slight unbalance in this ecosystem but compared to other methods it has virtually no effect on the environment.

 

Did you observe an increase in turbidity over time? Which of the two simulations is more turbid? Explain.

 

An increase in turbidity over time was observed. The second simulation was the more turbid because the fertilizer increased microbial growth and enhanced oil degradation.

 

Did you observe more fungal and bacterial growth in the test tubes or in the jars? Explain.

 

The jars showed more fungal and bacterial growth because of the nutrient fertilizer and there was more space for growth in the jar.

 

Bases on the information provided, do you think that the microorganisms would be affected by water temperatures? Would they follow the floating oil or be dissipated by shifting winds or currents? And if they did eat the oil, would the residue damage marine life?

 

The microorganisms would definitely be affected by changes in temperature. These organisms grow best at fairly warm temperatures, and growth would be minimal in colder conditions. The microorganisms grow directly on the oil and would therefore not be dissipated by shifting. No harmful residue has been found after using bioremediation. All that is left after this method is masses of food and non-toxic living cells.

 

Based on the physical characteristics of oil and water discuss possible resulting problems associated with oil spills.

 

Because oil and water do not mix, oil can be spread over vast areas of oceanic surface if it is not contained. After emulsification, oil forms a thick, viscous substance that adheres to anything it comes in contact with. Also oil prevents light from reaching the lower areas of the ocean and reduces plant growth.

 

In this investigation, we evaluated the ability of microbes to degrade oil under optimum conditions. Based on your findings, discuss possible environmental limitations in using such a method over an actual oil spill in the ocean.

 

The temperature at an actual oil spill site could not be controlled and may drop below the microorganisms’ range of temperature that it can live. Also lower temperatures may reduce the rate of degradation. The oil may be further spread and dispersed by shifting winds making it harder for the microorganisms to cover its surface.

 

If you had to decide which clean up method to use in an actual spill, would you use such a bioremediation method or use a mechanical method described in the introduction? Explain your decision.

 

In an actual oil spill situation, a combination of bioremediation and mechanical methods would probably be most effective. Absorbent materials such as cloth, straw, powdered clay, or pine bark, could be used to contain the oil spill, while bioremediation is allowed to break down the oil into its harmless components.

 

Assuming that you need 10-6 lbs. of highly concentrated cell mass mixed with the nutrient fertilizer for the degradation of oil covering 0.022 sq. ft, as in the simulated oil spill, estimate the amount of cell mass and fertilizer mixture in pounds that would be needed to degrade the oil covering 1 square mile of an ocean. Assume there is the same amount of oil relative to the area.

 

12,672 lbs. would be needed to degrade one square mile of ocean.

Investigation #3: Simulated Oil Spill along the Shore

 

Describe the physical and chemical changes of the oil after several days of microbial degradation.

 

The oil began to get darker and lose its slick qualities. It no longer covered the entire surface of the water and was separated into sections. The chemical changes that occur, are that the carbon bonds are oxidized and broken into smaller hydrocarbon chains.

 

How effective do you think such a method is when used in an actual oil spill on the shore?

 

The dryer, sandier areas would slow the degradation process and inhibit the microorganisms from reaching parts of the oil spill, however, although slower, the method would still be fairly effective.

 

Discuss the physical limitations of using a mechanical method to clean up an oil spill on the shore. What are the limitations of using a bioremediation method? Which of the two methods would be most efficient and economical to clean up oil spills?

 

Mechanical methods would be virtually impossible to use in shoreline cleanup especially without further damaging the local wildlife. Rocks and other physical barriers would prevent skimming or absorbing the oil. Bioremediation would also be slightly hindered by these physical barriers, but it would still be the most efficient and economical way to cleanup a shoreline area.

 

Discuss the effect an oil spill on the shore would have on plant life along shorelines, protists and other larger animals.

 

Oil components are usually toxic to most organisms. Marine birds and mammals are especially effected by oil spills. They lose their ability to float on water and their insulation against cold, which can leave them severely handicapped or dead.

 

In the Alaskan oil spill, chemical detergents were not used. Why? Explain the use of detergents.

 

Chemical detergents were not used in the Alaskan oil spill because most of these chemicals are toxic to benthic, littoral, and open water marine life.

 

Discuss the potential of bioremediation procedures in detoxifying the air, water, soil, and waste materials.

 

Bioremediation has great potential for cleaning oil out of any type of medium as long as the microorganisms are able to grow in that environment. The microorganisms may be able to be genetically modified to grow on other mediums and even become airborne, however genetic engineering is still very controversial at this time.

 

What can be done to prevent oil spills.

 

Oil spills could be prevented by strict government regulation of all oil transportation and general public concern for the subject. Carefulness is the main key in preventing oil spills since most are caused by human error. Other methods of prevention could include new fuel sources or other means of transportation such as aircraft or truck.

 

How are we affected by oil spills? Discuss the physical, environmental, and economic consequences of oil spills.

 

Oil spills cause severe damage to the environment which can in turn effect humans. Oil spills are extremely wasteful and can cost millions of dollars to clean. Oil is also a non-renewable resource, which means that every time an oil spill occurs tons of oil are lost forever.

 

Research other energy sources that can be used to cut our dependence on oil?

 

Hydroelectricity, solar power, and wind power are all alternative energy sources that could reduce our dependence on oil. However, none of these sources are efficient enough to replace our need for oil. Nuclear power plants have began to grow, but these plants are highly expensive and dangerous. A last alternative to oil, could be gasohol, which is an alcohol made from corn that can be burned for fuel.

 

Error Analysis

 

Errors in this lab could be caused by incorrect measurements, insufficient oxygenating of the specimens, or mishandling of the sterile equipment. The tubes in Investigation #1 were not consistently inverted. The potency of the Penicillium culture was also questionable and there was no visible fungal growth in the original Luria broth culture.

 

Discussion and Conclusion

 

Investigation #1 acted as a control for the next two simulations. It showed that microbial growth and degradation did occur in a controlled environment. It could be used as a comparison to the amount of oil degraded in the other simulations to see if the variables had any effect on oil degradation. Investigation #2 was a simulation of an actual ocean oil spill with the use of a nutrient fertilizer. The nutrient fertilizer did speed oil degradation and a large amount of the oil was completely degraded in both jars. In Investigation #3, a shoreline cleanup was simulated with the addition of sand to the petri dish. The sand slightly hindered the effectiveness of the microbial degradation, but it was still effective in the partial breaking down of the oil.

All three investigations showed that the Pseudomonas culture was slightly more effective than the Penicillium culture in oil degradation. This may have been caused by a higher rate of reproduction in bacteria than in fungi.